We present that two spin defects (SDs) can be entangled through a magnon polariton mode, within the strong-coupling regime. The magnon polariton modes are provided by an antiferromagnetic (AFM) MnF2 layer, where the dispersion of the modes is characterized by the layer's thickness. The macroscopic quantum electrodynamics theory is used to describe the light-matter interactions, where the Green's functions are its core elements. The individual SD relaxes by exciting the magnon polariton modes, exhibiting high enhancement values of the Purcell factor. When two SDs are considered, an oscillatory exchange of population probability is observed between them, a sign of strong-coupling light-matter interactions, where the concurrence value is used to quantify the level of entanglement. The thinner AF layers can potentially be used to promote interactions between multiple spins through long-range coupling. This is a desired feature to fabricate high-demand applications in the fields of quantum measurement and computation.
As individual photons move in the quantum regime, scientists describe the relevant light sources as quantum emitters that can be embedded in nanodiamonds, among others. These special diamonds are characterized by their very small particle size, which can range from just a few to several hundred nanometres. Researchers at the University of Münster have now succeeded for the first time in fully integrating nanodiamonds into nanophotonic circuits and at the same time addressing several of these nanodiamonds optically. In the process, green laser light is directed onto colour centres in the nanodiamonds, and the individual red photons generated there are emitted into a network of nano-scale optical components. As a result, the researchers can now control these quantum systems in a fully integrated state. The results have been published in the journal Nano Letters.
Quantum Entanglement Mnf Full Version
On-chip integration of single-photon detectors and reconfigurable optical circuits is a crucial step toward a fully scalable approach to quantum photonic technologies1. By confining light inside lithographically patterned waveguides, single photons can be actively routed2,3,4 and interfered5,6,7 in miniaturized reconfigurable optical networks, and their state can be read out with on-chip detectors8,9. Integration of these two key elements on a common platform enhances the scalability of quantum photonic devices by minimizing their footprint and eliminating the need for lossy interconnects between separated optical systems.
Although electrical crosstalk prevented us to show high-speed modulation at the full half-wave voltage of the EOM, this problem might be overcome in future experiments with appropriate improvements of our setup (see the discussion in Supplementary Note 2). Alternatively, for fast switching operations in the GHz regime, the length of the modulator can be increased in order to achieve a lower\(\,V_\rm\pi \). Thus, after complementing fast optical switches and single-photon detectors with ultra-low loss integrated optical delay lines55, our technology can also assist the development of universal quantum photonic processors by providing a powerful approach for the implementation of the spatial- and time- multiplexing schemes required for scalable linear optical quantum computing26, as well as the manipulation of photonic cluster states via single-photon detection measurements with active fast feedforward27. 2ff7e9595c